Sökning: "dynamic vegetation model"

Visar resultat 21 - 25 av 36 uppsatser innehållade orden dynamic vegetation model.

1. 21. Emulators for dynamic vegetation models - Supervised learning in large data sets

   Master-uppsats, Lunds universitet/Matematisk statistik

   Författare :Olof Olsson; [2017]
   Nyckelord :Gaussian process emulator; DGVM; emulation; Mathematics and Statistics;

   Sammanfattning : The observed and expected changes in the environment due to human actions implies risks that future food production will be insufficient. Pre- dicting the impact these changes have on the agricultural system could be beneficial by allowing for proactive mitigating efforts. LÄS MER

3. 22. Identifying potential critical transitions in a forest ecosystem using satellite data

   Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

   Författare :Krishna Lamsal; [2017]
   Nyckelord :early warning; critical transition; tipping point; EVI; time series; GEM; Earth and Environmental Sciences;

   Sammanfattning : Ecosystems can undergo changes that are slow and gradual, or an abrupt change - a sudden nonlinear dynamics that can bring catastrophic changes and ultimately leads to the change in the structure and functioning. Non-linear and discontinuous changes sometimes may cause the system to shift into another undesirable state, called ‘regime shifts’ or ‘critical transition’. LÄS MER

4. 23. Modelling global Gross Primary Production using the correlation between key leaf traits

   Kandidat-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

   Författare :Alexandra Pongrácz; [2017]
   Nyckelord :ecosystem modelling; leaf longevity; leaf nitrogen content; leaf mass per area; LEIA; LPJ-GUESS; GPP; terrestrial biosphere; Earth and Environmental Sciences; Biology and Life Sciences;

   Sammanfattning : Sophisticated ecosystem models make it possible to evaluate the potential future changes of the carbon sequestration capacity of the terrestrial biosphere, as a response to the rapid environmental and climatic changes. Accuracy of model estimates is however strongly dependent on the parametrisation of driving parameters. LÄS MER

5. 24. Evaluating the benefit-cost  ratio of groundwater abstraction for additional irrigation water on global scale.

   Master-uppsats, KTH/Mark- och vattenteknik

   Författare :Mohammad Faiz Alam; [2016]
   Nyckelord :Groundwater; Irrigation; Abstraction; Cost-benefit analysis; Global;

   Sammanfattning : Projections show that to feed a growing population which is expected to reach 9.1 billion in 2050 would require raising overall food production by some 70 percent by 2050. One of the possible ways to increase agricultural production is through increasing yields by expanding irrigation. LÄS MER

7. 25. Can the introduction of the topographic indices in LPJ-GUESS improve the spatial representation of environmental variables?

   Master-uppsats, Lunds universitet/Institutionen för naturgeografi och ekosystemvetenskap

   Författare :Alejandra Narváez Vallejo; [2016]
   Nyckelord :smooth topography; drainage area; slope; topographic wetness index; LPJ-GUESS; GIS; physical geography and ecosystem analysis; geography; geographic information systems; leaf area index; spatial patterns; MODIS LAI.; Earth and Environmental Sciences;

   Sammanfattning : Ecosystem modelling is an always evolving science trying to catch the complexity of the nature and its principles to model environmental responses in a realistic way. Over and over, models try to introduce more variables and interactions to achieve better representations of phenomena of interest like the responses of the ecosystem to a fast changing world (climate change, land use change). LÄS MER